Genomic Insights into Edwardsiella ictaluri: Molecular Epidemiology and Antimicrobial Resistance in Striped Catfish (Pangasianodon hypophthalmus) Aquaculture in Vietnam.

Edwardsiella ictaluri is responsible for causing bacillary necrosis (BNP) in striped catfish (Pangasianodon hypophthalmus) in Vietnam. This study offers a comprehensive genomic characterization of E. ictaluri to enhance understanding of the molecular epidemiology, virulence, and antimicrobial resistance. E. ictaluri isolates were collected from diseased striped catfish in the Mekong Delta. The species was confirmed through PCR. Antimicrobial susceptibility testing was conducted using minimum inhibitory concentrations for commonly used antimicrobials. Thirty representative isolates were selected for whole genome sequencing to delineate their genomic profiles and phylogeny. All strains belonged to ST-26 and exhibited genetic relatedness, differing by a maximum of 90 single nucleotide polymorphisms. Most isolates carried multiple antimicrobial resistance genes, with the tet(A) gene present in 63% and floR in 77% of the genomes. The ESBL gene, blaCTX-M-15, was identified in 30% of the genomes. Three plasmid replicon types were identified: IncA, p0111, and IncQ1. The genomes clustered into two clades based on their virulence gene profile, one group with the T3SS genes and one without. The genetic similarity among Vietnamese isolates suggests that disease spread occurs within the Mekong region, underscoring the importance of source tracking, reservoir identification, and implementation of necessary biosecurity measures to mitigate spread of BNP.

Comparative genomic analysis of Aeromonas dhakensis and Aeromonas hydrophila from diseased striped catfish fingerlings cultured in Vietnam.

Introduction: Motile Aeromonas septicemia (MAS) is a burden for striped catfish (Pangasius hypophthalmus) farmers in Vietnam. MAS can be caused by several species of Aeromonas but Aeromonas hydrophila is seen as the leading cause of MAS in aquaculture, but recent reports suggest that A. dhakensis is also causing MAS. Methods: Here we investigated the bacterial etiology of MAS and compared the genomic features of A. hydrophila and A. dhakensis. We collected 86 isolates from diseased striped catfish fingerlings over 5 years from eight provinces in Vietnam. Species identification was done using PCR, MALDI-TOF and whole genome sequence (WGS). The MICs of commonly used antimicrobials was established. Thirty presumed A. hydrophila isolates were sequenced for species confirmation and genomic comparison. A phylogenetic analysis was conducted using publicly available sequences and sequences from this study. Results: A total of 25/30 isolates were A. dhakensis sequence type (ST) 656 and 5/30 isolates were A. hydrophila ST 251. Our isolates and all publicly available A. hydrophila isolates from Vietnam belonged to ST 251 and differed with <200 single nucleotide polymorphisms (SNP). Similarly, all A. dhakensis isolates from Vietnam belonged to ST 656 and differed with <100 SNPs. The tet(A) gene was found in 1/5 A. hydrophila and 19/25 A. dhakensis. All A. hydrophila had an MIC ≤2 mg/L while 19/25 A. dhakensis had MIC ≥8 mg/L for oxytetracycline. The floR gene was only found in A. dhakensis (14/25) which showed a MIC ≥8 mg/L for florfenicol. Key virulence genes, i.e., aerA/act, ahh1 and hlyA were present in all genomes, while ast was only present in A. dhakensis. Discussion: This study confirms previous findings where A. dhakensis was the dominating pathogen causing MAS and that the importance of A. hydrophila has likely been overestimated. The differences in antimicrobial susceptibility between the two species could indicate a need for targeted antimicrobial treatment plans. The lipopolysaccharide regions and outer membrane proteins did not significantly differ in their immunogenic potentials, but it remains to be determined with in vivo experiments whether there is a difference in the efficacy of available vaccines against A. hydrophila and A. dhakensis.

Multiple serous membrane effusion caused by primary pericardial mesothelioma.

Primary pericardial mesothelioma is an extremely rare cancer with a short survival prognosis. Clinical symptoms are often atypical, and most patients are diagnosed after surgery or at autopsy. We report a case of a 35-year-old female patient with multiple serous membrane effusion for more than 1 year. The patient underwent pericardial, pleural, and peritoneal fluid drainage many times and underwent many laboratory tests to find the cause; however, there was no definitive diagnosis. She was admitted to the hospital because of shortness of breath, cough, and sputum for 5 days. She underwent extensive pericardiectomy to resolve the dyspnea and pericardial surgery to find the cause of the multiple serous membrane effusion. After surgery, her dyspnea was relieved, and the serous effusion gradually decreased.

Surgical treatment of tension pneumomediastinum in patients with covid-19 at the field hospital: a case series.

BACKGROUND: Tension pneumomediastinum is one of the most serious complications in COVID-19 patients with respiratory distress requiring invasive mechanical ventilation. This complication can lead to rapid hemodynamic instability and death if it is not recognized in a timely manner and intervenes promptly. CASE PRESENTATION: We reported 7 COVID-19 patients with tension pneumomediastinum at a field hospital. All patients were critically ill with ARDS. These 7 patients, including 3 females and 4 males in this series, were aged between 39 and 70 years. Tension pneumomediastinum occurred on the first day of mechanical ventilation in 3 patients and later in the course of hospital stay, even 10 days after being intubated and ventilated. The tension pneumomediastinum caused hemodynamic instability and worsened respiratory mechanics with imminent cardiopulmonary collapse. In this series, we used two surgical techniques: (i) mediastinal decompression by suprasternal drainage with or without simultaneous pleural drainage in the first two cases and (ii) mediastinal drainage via suprasternal and subxiphoid incisions in 5 patients. The surgical procedures were feasible and reversed the pending cardiopulmonary collapse. Four patients had a favorable postprocedural period and were discharged from the intensive care center. Both patients undergoing suprasternal drainage died of failed/recurrent tension pneumomediastinum and nosocomial infection. Only one in five patients who underwent mediastinal drainage via suprasternal and subxiphoid incisions died of septic shock secondary to ventilator-associated pneumonia. CONCLUSION: Tension pneumomediastinum was a life-threatening complication in critically ill COVID-19 patients requiring mechanical ventilation. Surgical mediastinal decompression was the salvage procedure. The surgical technique of mediastinal drainage via suprasternal and subxiphoid incisions proved an advantage in tension relief, hemodynamic improvement and mortality reduction.

Acute Pulmonary Embolism Associated with Low-Dose Olanzapine in a Patient without Risk Factors for Venous Thromboembolism.

BACKGROUND: Olanzapine is a second-generation antipsychotic drug commonly prescribed for certain mental/mood conditions such as schizophrenia and bipolar disorders. This agent has been considered a precipitating factor for venous thromboembolism formation. Most of the cases previously reported were associated with high-dose olanzapine therapy or in patients with high-risk factors for the development of thromboembolism. Case Presentation. We report a patient who developed pulmonary embolism after a long course of low-dose olanzapine. A 66-year-old female patient suffering from insomnia had been prescribed olanzapine 2.5 mg and paroxetine 10 mg for two years. The patient suddenly developed a syncopal episode at home and was immediately brought to the hospital. The diagnosis of pulmonary embolism was made by chance during the computerized tomography of coronary arteries. The patient made a full recovery under conventional treatment and was discharged in stable condition. The thoracic computed tomography taken two months after discharge showed a completely normal pulmonary arterial tree. CONCLUSION: Olanzapine-associated pulmonary embolism is a rare entity and might be missed if the physician in charge is not vigilant and well informed. Even low-dose olanzapine can be associated with pulmonary embolism in patients with low classic risk factors if the treatment is prolonged. Pulmonary embolism should be sought in patients taking olanzapine even though the presenting manifestations are nonspecific.

Severe aortic regurgitation following blunt chest trauma due to home accident.

Aortic valve rupture is a rare manifestation in comparison to cardiac rupture or contusion following blunt chest trauma. We report a case of aortic valve leaflet rupture with severe aortic regurgitation after a fall from a ladder. The aortic valve rupture had been missed in the emergency ultrasound and was only detected on comprehensive echocardiography after failure of weaning from a mechanical ventilator. The patient underwent aortic bioprosthetic valve replacement that dramatically changed the clinical course.